The present invention generally relates to spring wire cores for use in seat cushions, mattresses and the like. More particularly, the invention relates to a formed wire mattress assembly intended for use as a primary bedding mattress having the advantages of component assembly at the upholstery facility.
While primary bedding mattresses are known to exist in a variety of styles, the most common forms are comprised of coil springs, continuous or individual, aligned in rows that form a generally rectangular shape. Lacing wires on the top and bottom surfaces of the coil springs hold the coil springs in place and provide for a yieldable core. A border wire, that conforms to the rectangular shape of the entire coil assembly, is then affixed to each of the top and bottom surfaces to define the perimeter of the coil mattress core.
When shipping the assembled cores to the upholstery manufacturer, packaging requires the full compression of fourteen to twenty cores and the use of crating material and baling wire ties to prevent decompression. Heavy unbaling equipment is required at the upholstery facility to reverse the packaging process and control the dangerously high loads involved. The storage space required to house the fully expanded and unused portions of the unbaled cores can be a significant problem.
Another variety of mattress assembly, herein referred to as a secondary bedding mattress, is illustrated in U.S. Pat. No. 4,475,724 which is commonly assigned to the assignee of the present application. The mattress assembly of the '724 patent is a wire spring assembly for a sleeper sofa. The assembly consists of a number of resilient wire spring units which are secured to one another and arranged in rows so that the entire assembly is allowed to flex as it is folded into or out of the sleeper sofa. This type of wire formed mattress assembly, has distinct advantages over a coil assembly. Because the lacing wire method of attaching the coils is omitted, the noise created by the lacing wires is eliminated and a more economical use of wire is achieved. However, this assembly is not suitable as a primary bedding mattress from the standpoint of user comfort. One problem is the low height required for sofa/sleeper mattresses cannot provide the proper contour loading necessary for long term usage.
It is therefore an object of the present invention to provide for the production of a formed wire mattress assembly specifically intended for use as a primary bedding mattress.
Another object of the present invention is to decease the number of components required in the formed wire mattress assembly to allow for knock down shipment of parts and assembly of the core at the upholstery facility.
It is a further object of this invention to enable style and firmness changes in the mattress through individual component substitution rather than full assembly substitution.
Yet another object of this invention is to provide a mattress assembly which offers a substantial amount of support along the edge or perimeter areas of the assembly.
The present invention also has as an object eliminating the use of coil springs in a mattress assembly.
Another object of this invention is to provide a mattress assembly which offers the same support characteristics on both its top and bottom surfaces.
And still another object of this invention is to provide a mattress assembly which incorporates spring units that may vary in gage, style and function to control the behavior characteristics of the mattress assembly.